Overfilling engine oil to 12L+ (video)

[Maximus Gladius]

This happened to me when I received my second engine back in the Fall of 2022. When the new engine was installed, the tech made a mistake assuming the crate engine was shipped dry, but was full and my service order said he ordered 6L and put that in. Because 12L came out, I can only assume it came overfilled with 6 from the factory and the tech put 6 more in.

After I received the truck I immediately had to get to BC on a business trip. The 1567km highway trip from Alberta involves summiting several high elevations through the Rocky Mountains, there and back. When I got home I did my first oil change and discovered the 12L and that the PCV had sent a massive amount of oil through the intake and was pooling in the intake manifold and was just making its way down the runners. I had no external oil leaks and no smoke

I found this cool video on just what happens when an engine is overfilled with oil and they take it to 12L + and past the point the PCV is puking the oil through.

So for those of you wonder being over the full line by 1/2 quart or maybe your engine holds 5 but the tech put in 6?? …watch this video.


And this video is also a great idea as to what to do if your engine doesn’t have a dipstick

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[Lunentucker]

I had watched that one a while back. That's when I decided that if I ever did decide to do any high angle crawling that maybe an extra quart might not be a bad idea on a temporary basis.

 

[ShadowsPapa]

Be careful when watching videos like that made with a specific engine - older design, compared to the modern 3.6
The 3.6 has a built-in windage tray for one thing, and the crankcase/pan shape is very different.
The amount an engine can handle will vary greatly with that engine.
Many V8s that specify 5 can easily handle 6 to 6.5 with no issues at all.
Others are going to see foaming and issues at far less than our 3.6 will handle.
The 3.6 PUG in the JT has proven over and over 6 quarts is no issue. I say that because of the many thousands of Jeep owners who use the WAVE services, or simply take their vehicle into the dealership for oil changes regardless of WAVE. No, most Jeep owners don't do their own maintenance.
In the beginning months of the JT many 3.6 engines got 6 quarts - and no one knew, the owners drove them until the next oil change. If they didn't check, and why would they? then it went for thousands of miles that way - just fine.

The AMC V8s were another example of "6 is fine" because after a really hard run, then a quick deceleration, there was so much oil up top and the hard slow down forced oil in the pan to fly forward, oil pressure dropped for 1 or 2 seconds until you stopped and the oil settled back into the sump again. So we ran an extra quart if we were the sort that ran them hard. (or restricted the feed to the rockers by blocking off the push rod passages, aided return flow by polishing the valley's drain holes and so on)

One doesn't really need a video to know what happens. Aeration of the oil, raising the level even MORE, whipping the oil like hurricane force winds whip the ocean or gulf water, leaving a lot of water drops in the air - in the engine, a lot of oil mixed in the air in the crankcase.
You also get more into the cylinders due to the uncontrolled amount of oil on the cylinder walls which the rings can no longer handle.
There would be a loss of oil pressure because the air in the aerated oil can be compressed, bearing damage may result.

Luckily, our engines are fine with 1 quart over. And if on extreme hills/angles, it's not a bad idea. One drawback of an ICE on hillsides is that you can starve them for oil quite easily.
If I was doing hardcore crawling, I'd probably add a quart to prevent that.

 

[Maximus Gladius]

Be careful when watching videos like that made with a specific engine - older design, compared to the modern 3.6

Since having to deal with the overfill on my engine and experiencing all that oil in the upper parts via the PCV, I always wondered what the level of 12L of oil in relation to the crankshaft looked like. I wasn’t burning oil that I could see but after taking my plugs out and seeing the condition of those, I can’t be sure if the splash around the cylinders was an issue or if the mess in the intake manifold was culprit? When I had the manifold off and filled it up with brake cleaner and sloshed it around a few times and saw all that crap get washed out and seeing the oil residue near the valves, I’m leaning on the mess up top was causing my plugs to foul and look bad.

I realized, as you said, that we’re talking two different engines and that’s fair but it sure was interesting to see what it takes to see the PCV to spew oil. Thanks for your input.

 

[ShadowsPapa]

We're lucky with a built-in windage tray. With the shallow sump we have, and running at a strong pitch or roll............. oil is going to make it's way up higher.

The crankshaft throws don't have to touch the oil to foam things up - other engines run with enough to get too close to the throws or ends of the rods will see that the wind or air itself will pick up the oil and toss it around. Think of a helicopter over the water.
The shape of the pan also matters - we've got a pretty shallow pan so I can imagine double the oil could cause a lot more issues than with some that have much deeper "sumps".

Windage tray or not - double the oil? I'd not be surprised if the air movement in the 3.6 is enough to cause so much oil in the air that the cyclonic effect of the separator at the PCV can't keep up.

You saw what you saw, no one can argue "didn't happen" or "not possible" - you can imagine what was going on in that engine.
The pictures of the valves and that area were amazingly clean for what it went through earlier.

 

[ShadowsPapa]

BTW- since these guys are Russian (and amazing as well) I wonder what engine they are using. Just curious. They've done some really crazy stuff over the years, including remaking crankshafts and more.

 

[evoarie]

True story:
Years ago I worked at parts counter at a parts store. After closing one night the cashier comes up ask me why his car took so much oil. I asked him how much he was using, and he should see signs of leaks or smoke out the tail pipe. He tells me no hes not seeing that of but puts a quart in every day. He said he keeps it filled to the top. Ugh, top of what I ask. He replied to the fill cap. lol. He was driving a 4 cylinder Japanese, don’t remember the make. It was at night, couldn’t see if the oil was really that high, but I set him straight, and was amazed it was running.

 

[JTGuy]

Just did my first oil change after the dealer wave did 3.
Findings::::
Drain plug was stupid tight.
Filter cap OK but a little tight.
Measured oil out at 5.5 quarts.
Wondering if 5.5 would be a good idea for fill??
In general the dealer did a good job with the oil changes but I wonder how many more times the drain plug would take the torque used on it.

 

[Mr._Bill]

Just did my first oil change after the dealer wave did 3.
Findings::::
Drain plug was stupid tight.
Filter cap OK but a little tight.
Measured oil out at 5.5 quarts.
Wondering if 5.5 would be a good idea for fill??
In general the dealer did a good job with the oil changes but I wonder how many more times the drain plug would take the torque used on it.

It's listed as only needing five Quarts, but a little extra doesn't hurt. Some might say that extra half helps it run a little cooler. They may do it so they don't have to teach the changer how to tell the difference between the ones that need five or six.

The dealer did the first seven changes on my first Gladiator. They were pretty rough on the Drain plug. I bought a new one to make things easier for me.

Dorman 090-938CD Oil Drain Plug Pilot Point M14-1.50, Head Size 13Mm Compatible with Select Models https://a.co/d/akNpmOP

 

[MrBones]

Reviving this thread with my recent experience.
Got my first oil Jeep Wave change yesterday. Here's what the work description on the receipt said:

"6 Qt. 5W-20 synthetic oil"

Wrong on two counts. From the above discussion, I guess one extra quart is no big deal. And since I'm in Southern California where the overnight temps rarely get below 40F this time of year I'm figuring that 5W-20 isn't a big deal either but this dealer is off my list. Next oil change will be 0W-20.

 

[Mr._Bill]

Reviving this thread with my recent experience.
Got my first oil Jeep Wave change yesterday. Here's what the work description on the receipt said:

"6 Qt. 5W-20 synthetic oil"

Wrong on two counts. From the above discussion, I guess one extra quart is no big deal. And since I'm in Southern California where the overnight temps rarely get below 40F this time of year I'm figuring that 5W-20 isn't a big deal either but this dealer is off my list. Next oil change will be 0W-20.

Did you question the dealer about it? I did, because it was listed wrong on my first oil change. He told me that the truck got what it was supposed to have, and they had a generic entry in the invoicing system that they used for the free oil changes. I put almost 60k miles on that truck, with no engine issues. I only did two of the oil changes, the dealer did all the others.

 

[MrBones]

Not yet. I was late for another appointment but that thought crossed my mind. I did recall a similar instance with another car. My cobra took six quarts and the dealer (Same company) said they added five quarts. They actually added six.

 

[TheRealStreetcommander]

I fill to 6 quarts intentionally, and use 0w40 or 5w40 oil. No crank strike at 6qts. No negatives at all from filling to 6 quarts, only positives. The factory transition from 6 to 5 quart fill directive was based on environmental scoring targets, not for any engineering purpose. This is true for the extended OCI’s as well.

It’s prudent to keep in mind that most of these factory maintenance recommendations are a compromise position and not intended to achieve the greatest potential useful life. The factory only needs to get a vehicle beyond warranty and beyond its first owner.

 

[Hootbro]

I fill to 6 quarts intentionally, and use 0w40 or 5w40 oil. No crank strike at 6qts. No negatives at all from filling to 6 quarts, only positives. The factory transition from 6 to 5 quart fill directive was based on environmental scoring targets, not for any engineering purpose. This is true for the extended OCI’s as well.

It is always something new and odd with you.

With the current PUG generation Pentastar, the whole lower end to include the windage oil tray was redesigned and hence the change from 6 quarts to 5 quarts. The dry fill for the motor is 5.7 quarts, so 0.7 quarts never drain at each oil change. I see no benefit of sticking 6 quarts in there when it was not designed for it.

PPE does sell an oil pan that will give you an extra 0.75 quarts if that is your thing.

 

[TheRealStreetcommander]

It is always something new and odd with you.

LOL. That's the best and most genuine compliment I've gotten in a long, long time.

I try and look at these things objectively.

Probably better than 99% of oil-related engine failures are from folks failing to check their oil level, resulting in oil contaminate concentration cycled through the bearings/interface surfaces, and eventually oil starvation. This is intensified by extended oil change intervals. Most manufactures, including Jeep, allow for silly levels of permissible oil consumption --sometimes as great as 1 quart every ~1000 miles. Even at only a third of that maximum "okay" consumption rate, a 5 quart fill would be at 2 quarts in the sump after 9k miles. What is the greater danger, overfilling by a quart or falling victim to typical human behavior?

No one has ever lost an engine from overfilling by 1 quart.

And yes, limiting oil capacities and increasing maintenance intervals are absolutely a design criteria forced on powertrain engineering teams.

None of this is worth fighting over, but it does warrant some thought.

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